[Problems in diagnosis of necrotic angiitis of the tongue].

Cutaneous and mucous lesions are uncommon and very often confusing in Horton's disease. In this case report, adding to this confusing aspect, the patient's medical history and clinical signs led the investigations in a totally different direction. Facing this isolated lesion of the tongue and the negative biopsy of the temporal superficial artery, the diagnosis of Horton's disease was finally confirmed by the good reaction following corticoid therapy.